WOW. That's fantastic. As I noted in a comment above, I wrote a tool called crabby that uses Selenium and Chrome headless to do automated page testing and to report results back to metrics engines like Graphite, Datadog, Prometheus, and Riemann. The biggest problem I have is the unreliability of chromedriver and the extreme resource consumption of Chrome + Selenium. It's really too much for your average public cloud instance if you want to test any more than, say, one or two pages a minute.

Do you know if chromedp can access any of the timing measurements?